Controllable semiconductor rectifier with interference potential compensation

Abstract

A controllable semiconductor rectifier which is subject to an interference potential and controllable by a control power comprises a first emitter layer, a first main electrode connected to the first emitter layer, a control base layer connected to the first emitter layer, a main base layer connected to the control base layer and a second emitter layer connected to the main base layer. A connection is established between a portion of the control base layer and the first emitter layer for applying a compensating potential to the first emitter layer for compensating the interference potential and a limiting non-linear component is connected between a portion of the control base layer and the first emitter layer for limiting the interference potential.

What is claimed is: 
     
       1. In a controllable semiconductor rectifier controllable by a control power and exposed to an interference potential, having a plurality of layers of different conductivity types, two outer layers thereof being provided with main electrodes and one of the outer layers adapted to be an electron or hole emitter having an area which is ignitable by the control power to be supplied and which upon occurrence of the interference potential receives a compensation potential which goes in the same direction as the interference potential of the adjacent intermediate layer in the area fired primarily by the control power, the improvement comprising means connected between said one outer layer adapted to be an electron or hole emitter and the adjacent intermediate layer for limiting the interference potential of this layer. 
     
     
       2. A semiconductor rectifier according to claim 1, in which an ignition potential characteristic curve of the semiconductor rectifier has a main width which is narrower than the main width of a limited interference potential characteristic curve of a limited interference potential and said limiting means applying said limitation in the area of rise of the interference potential characteristic curve. 
     
     
       3. A semiconductor rectifier according to claim 1, wherein said limiting means comprises a non-linear element disposed in the area of occurrence of the interference potential of the adjacent intermediate layer which is connected with one of said main electrodes, said one of said main electrodes comprising a cathode-side connecting contact. 
     
     
       4. A semiconductor rectifier according to claim 3, wherein said non-linear elements comprises a semiconductor diode with a short forward recovery time. 
     
     
       5. A controllable semiconductor rectifier which is subject to an interference potential and controllable by a control power comprising, a first emitter layer, a control base layer connected to said first emitter layer, a main base layer connected to said control base layer, a second emitter layer connected to said main base layer, a connection between a portion of said control base layer spaced from said first emitter layer and said first emitter layer for applying a compensating potential to said first emitter layer to compensate for the interference potential and limiting means connected between said first emitter layer and a portion of said control base layer for limiting the interference potential. 
     
     
       6. A controllable semiconductor rectifier according to claim 5, wherein the control power comprises light and said limiting means comprises a semiconductor diode. 
     
     
       7. A controllable semiconductor rectifier according to claim 6 further including a first main electrode connected to a portion of said first emitter layer, a second main electrode connected to said second emitter layer, a portion of said first emitter layer disposed centrally in the control of the rectifier not connected to said first main electrode, said connection for the compensating potential connected between a portion of said control base layer adjacent an edge spaced from the center of the rectifier and said central portion of said first emitter layer, said diode connected between a portion of said control base layer adjacent said central portion of said first emitter layer and said first main electrode. 
     
     
       8. A controllable semiconductor rectifier according to claim 6 further including a first main electrode connected to said first emitter layer covering a major portion of said first emitter layer and leaving a central portion of said first emitter layer uncovered for exposure to light, a portion of said control base layer extending around said uncovered portion of said first emitter layer, said connection for the compensating potential connected between an electrode on said exposed portion of said first emitter layer and a substantially U-shaped electrode on exposed portion of said control base layer, said semiconductor diode connected between an electrode on said portion of said control base layer disposed around said exposed portion of said first emitter layer and said first main electrode. 
     
     
       9. A controllable semiconductor rectifier according to claim 5, wherein the control power comprises light, a first main electrode connected to said first emitter layer, a control base electrode connected to a portion of said control base layer spaced from said first emitter layer, a second main electrode connected to said second emitter layer, a capacitor connected between said first and second main electrodes, said first main electrode and said control base electrode connected to a zero potential terminal, a resistor connected between said zero potential terminal and each of said first main electrode and said control base electrode, and a diode connected between said control base electrode and said zero potential terminal. 
     
     
       10. A controllable semiconductor rectifier according to claim 7, wherein said diode is formed by doping in the vicinity of said first emitter layer. 
     
     
       11. A controllable semiconductor rectifier according to claim 5 further including means for providing a control current comprising the control power for controlling the controllable semiconductor rectifier.